In wireless communication, low-density parity-check (LDPC) codes, which are constructed using sparse matrices, are often used to correct erroneous linear block codes of which errors may occur during transmission. Under the circumstances that certain design specifications are conformed with, block codes that have longer codeword lengths usually have better error correction ability.
However, a longer codeword length leads to more redundancies, resulting in high costs in terms of software and hardware equipments for computation during encoding and decoding. In addition, in an application of, for instance, mobile wireless communication, different code rates that may be present in a transmission channel which is used for data transmission may limit a block size of to-be-transmitted data, thereby restricting the selectable codeword length for the block codes.